Millions of dollars in advertising were spent on this closely-watched recall campaign, with money pouring in from both sides. The recall efforts were spurred over a collective bargaining law that Walker pushed through legislation — the law stripped rights away from labor unions, who were some of Walker's most vocal critics.

Data also suggested that the passions either for or against Walker ran high in Tuesday's vote. The vast majority of voters made up their minds before May, and few voters who identified either as a Democrat or Republican crossed party lines to support a different candidate.

If he had lost the election, Walker would have been the third U.S. governor in history to be recalled.